The Ras-homologous (Rho) family of small GTPases (Rac, Cdc42 and Rho) are key regulators of actin reorganization, cell motility, cell-cell and cell-extracellular matrix (ECM) adhesion as well as of cell cycle progression, gene expression and apoptosis (FIG. 1) [1-8]. In many human cancers (including colon and breast), aberrant Rho-family signaling due to changes in the GTPase itself or in its regulation loops is a critical underpinning of tumor growth and survival, invasion and metastasis [9-13] (FIG. 1). RhoA and RhoC correlate with advanced ovarian cancer and peritoneal dissemination [14; 15]. Although Rac1 and Cdc42 have been recognized as attractive therapeutic targets, specific Rac GTPase inhibitors while effective in culture [16; 17] have not been translated to clinical use and there are no established Cdc42 specific inhibitors. Lovastatin was shown to inhibit Rho GTPase and reduce ovarian metastasis in a xenograft model [15]. However, the use of statins to block GTPase membrane association has met with only modest success due to their broad spectrum inhibition of protein prenylation resulting in pleiotropic effects on many GTPases and pathways [18]. Furthermore, recent animal studies wherein the effects of geranylgeranlytransferase type I deficiency were analyzed revealed an unexpected hyperactivation of Rho GTPases and concomitant severe joint inflammation {Khan, 2011}. Thus, more specific agents for clinical application for use as inhibitors of Cdc42 GTPase are urgently needed. The present invention seeks to meet that need.